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The Scie Peyton Manning jerseys nce of Trash

The Scie Peyton Manning jerseys nce of Trash

Peyton Manning jerseys pigment blue 1 Pigment blue 27 pigment orange 13 Pigment orange 16 Pigment orange 5 pigment red 122 pigment red 170 pigment red 176 pigment red 2 pigment red 48:2 pigment red 57:1 pigment red 81 pigment violet 19 pigment violet 23 pigment yellow 1 pigment yellow 12 pigment yellow 3 pigment yellow 74 plastic building blocks

The Science of TrashPublished: 24 Nov 2009 21:01:51 PST<p class="authorInfor"]</p]<P]Modern technology is being used to avert a trash crisis in Chinese cities

CLEANING UP: A wastewater treatment plant in Wuyuan County, Jiangxi Province was put into operation on November 28, 2007. The plant can treat 120 tons of wastewater daily (WANG GUOHONG)</P]<P]Few Beijingers who are enjoying the bustle of modern city life realize that they are being besieged by trash. If no measures were taken, Beijing would soon see itself in the middle of a garbage crisis, said Chen Yong, head of the Beijing Municipal Cityscape Management Commission. The volume of trash the city produces grows 8 percent annually. Officials project that more than 12 million tons of trash will be generated in Beijing each year by 2015.</P]<P]Researchers using remote-sensing technology in 1983 found that landfills were scattered between Beijing's Third and Fourth Ring roads. More than 4,700 of the dumps were larger than 50 square meters. The Beijing Municipal Government had invested 2.3 billion yuan ($338 million) to build waste treatment facilities to solve the problem.</P]<P]"Waste management requires science and technology for improvement," said Wu Wenwei, head of the Beijing Environmental Sanitation Engineering Research Institute. Wu said waste treatment technologies are progressing in two directions¡ªresearching commonly used landfill, incineration and compost technologies to reduce pollution, lower costs and increase recovery rates and developing other new methods to deal with trash.</P]<P]"The optimal solution is to produce little or no waste. The sub-optimal solution is to recover waste, and the third best option is to build waste treatment plants and strive to treat 100 percent of waste," said Wang Weiping, a senior engineer at the Beijing Municipal Cityscape Management Commission and a consultant to the Beijing Municipal Government. Wang, who has spent more than 20 years researching garbage, is one of many experts pushing for a fully circular economy.</P]<P]In recent years, Beijing has actively promoted waste reduction, reuse and recycling, as well as scientific waste treatment. The city has constructed a number of key facilities for waste collection, transportation and disposal, and is gradually building a multidimensional waste treatment system, said Yang Zhihui, Director of the Environment and Resource Section of the Beijing Municipal Development and Reform Commission.</P]<P]Recycle</P]<P]Beijing has been building large landfills and other treatment facilities since 1992.</P]<P]"Beijing's landfills are constructed according to national standards, with seepage control, leach ate collection and removal and bio gas collection systems. The landfill techniques are very complicated, and there are strict and clear technical specifications," said Wu. Every layer of waste, about 1 meter thick, is regularly sanitized, deodorized and covered with a layer of soil. The bottoms of landfills are covered with thick polyethylene films to prevent leakage and to protect groundwater and soil from contamination. Thick, black pipes dot the surface of the landfills and are used to collect bio gas from waste.

RECOVERING RESOURCES: Workers bag solid organic fertilizer at a biological treatment plant in Fengtai District, Beijing. The plant turns 400 tons of manure into solid organic fertilizer daily (DENG JIA/CFP)
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Beijing has 13 landfills, with a designed daily capacity of 10,400 tons. But on a single day last year, 17,400 tons of waste was treated, with 1,000 tons left unprocessed on a daily basis.</P]<P]There is a large landfill in Liulitun, Beijing's Haidian District, which is dozens of meters deep and is as large as about a dozen football fields. It was built in 1999 with a designed daily capacity of 1,500 tons. It was expected to reach capacity in 2017, but at its current rate of use, th¥«©`¥É ¬F½ğ»¯

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